An ambulance is one of the most electrically demanding vehicles on the road. It carries life-support and diagnostic equipment, communications, environmental control, warning and scene lighting, and powered patient-handling gear, all of which must work on scene, often with the engine off, and none of which can be allowed to strand the vehicle. A task and power management system is what ties all of that into one dependable, diagnosable whole.
What “task and power management” means
The term covers two linked jobs:
- Power management: making sure every load gets clean, protected power, and that the battery is never taken below the point where the vehicle can start.
- Task management: handling the vehicle’s control logic: switching, sequencing, interlocks and monitoring for all the built-in functions, from the saloon environment to the warning system.
On an ambulance these are inseparable. The power system decides what can run; the task system decides what does run and in what order.
The core requirements
A front-line ambulance build has to satisfy several demands at once:
- Load prioritisation. Medical and communications equipment must sit above comfort and convenience loads, so that if power is constrained the critical equipment is the last thing affected.
- On-scene power with the engine off. Combined with run-lock, the system keeps the alternator feeding the payload while the crew works, then manages the battery carefully if the engine stops.
- Graceful load-shedding. As battery voltage falls, non-essential loads are shed in stages, with warning to the crew, rather than everything dropping at once.
- Deterministic switching. Every function (beacons, scene lights, saloon systems, tail lift, environmental control) is switched through defined, programmable outputs, not a fragile loom of timers and relays.
- Monitoring and diagnostics. The crew and the workshop need to see load states, battery condition and faults, quickly.
How it is built
The electronic backbone is a set of programmable controllers and switching modules working together:
- Task and power management controllers. Intellitec’s IPLC and PMC families provide the processing, inputs, outputs, voltage monitoring and load control at the centre of the build. The IPLC carries a processor, multiple inputs and outputs, voltage monitors, a temperature sensor and a display in one rugged unit; the PMC Multiplex scales to a large channel count for complex vehicles. Quad H-Bridge and Load Manager modules handle motor and high-current loads such as powered equipment.
- CAN switching and keypads. iConnex keypads and switch panels give the crew a programmable interface where each switch is assigned a function in the control logic rather than hard-wired to a single load.
- Battery protection. A Battery Guard underpins the whole system, isolating non-essential loads before the starter battery is discharged, so the vehicle always cranks.
- Clean supply. DC-DC converters and, where needed, inverters keep sensitive medical equipment inside its rated supply window.
Intellitec’s controllers are used in exactly this role on NHS front-line ambulances.
Designing it well
- Define the load hierarchy first: what must survive an engine-stop, what may be shed, and in what order.
- Set shedding thresholds above the Battery Guard’s hard disconnect so the vehicle degrades gracefully.
- Make the crew interface clear: obvious switches, honest feedback on what is on and what has been shed, and a visible battery state.
- Build for diagnostics so faults are reported, not hunted, keeping vehicles available.
The goal is simple to state and demanding to deliver: full, reliable power to the crew on scene, critical equipment protected above everything else, and a vehicle that always starts and always tells you what it is doing. That is what a properly engineered task and power management system provides. Intellitec’s controllers, switching and Battery Guards are UK manufactured.